Tips ons rear hatch thunk and proper places to felt?

[kenyee]

Gilly,

I was hoping you had tips on what you've done to fix rear hatch thunks since I've gone to my dealer a few times to fix this and their adjustments only last a few months and I'm now out of the noise warrantee :-P
Specifically:
1) how do you adjust the latch at the bottom of the opening? What do you look for when adjusting it? Mine was "adjusted" by the dealer, but it looks tilted (the torx screws are not an even amount from the plastic) :-( Which torx screw do you use? These things look huge?
2) can you put felt around the latch? Some folks on the m-class mailing list mentioned their dealers put felt in, but I'm worried this will interfere w/ the locking mechanism and the door won't open.
3) is there a new latch assembly? If so, what's the part# and how does it look different?
4) can you put felt on the rear hatch where it contacts the rubber stops? It seems the thump is probably from the hatch whacking the rubber stops, so I'm surprised there's no rubber at the contact point on the door...

I'll write something up w/ pictures if you get a chance to answer these questions. Thanks :-)

ken

[Gilly]

You should update your profile so I'd know what year you have. Assuming it's an earlier model, you need to change the latch. The design was changed to get rid of the clunk, very well known problem. Like alot of early-model problems, they mostly have official fixes by now, mostly by replacing with the most current available parts. You'll need to remove the inner tailgate trim to do it, other than that it's a walk in the park to replace.
On the striker (part on the body sill) you usually CAN go by looks, centered up and not crooked, try centering fore/aft and see how it works and adjust fore/aft by how hard it is to close the hatch. If you hold the outside handle in the "unlatch" position and close/open very slowly, you shouldn't feel the latch dragging on the striker.
PS you can tell if you have an early or late style latch by looking in the VEE where the striker slides in, the updated ones you'll see a series of ridges towards the smallest end of the vee, the originals are all smooth.
Gilly

[kenyee]

I have a 2001 ML320. I'll take a pic of the striker. I don't remember any ridges, so I probably have the old one. The dealer made no mention of a new striker. Was there a TSB on it? And I doubt I'd be able to get it done for free since it's out of warrantee :-P

[kenyee]

Is this a picture of the old striker...definitely no ridges on mine?
Also, any idea what the torque should be for the striker's torx screws and what size the screws are?
Thanks :-)

[RickT]

Knock on wood...the rear hatch on my 99 ML is about the only thing that seems to work right.

Well I take that back, I recently discovered that it does not lock. But at least I have not had the common problem that you are referencing. I just wanted to suggest that in addition to the latch, that you can put some felt on the back of the liscense plate frame too.

[kenyee]

Good point on the license frame...I've heard some of them rattle like crazy on loaners. It sounds more like a buzz though.

This is a distinct thunk which the dealer has fixed once already by adjusting the rubber stops outwards. The rubber stops are now deformed w/ indentations from the hatch, so that's probably one reason it occasionally thunks (and the left stop wiggles like it's about to fall out)-:

Your problem is relatively easy to fix. I clipped someone's notes on fixing it:
http://www.keysolutions.com/M-Class.nsf/aac7d56ca8fd884b852563be00610639/9ccce0546c7ef00b85256e4a007aec4d

[Gilly]

You're looking for the ridges on the wrong part!

PS you can tell if you have an early or late style latch by looking in the VEE where the striker slides in, the updated ones you'll see a series of ridges towards the smallest end of the vee, the originals are all smooth.

Gilly

[kenyee]

Originally Posted by Gilly

You're looking for the ridges on the wrong part!

Oops

Here's a pic of the striker on the bottom of the hatch door

Do you have the DTB or TSB that describes the use of the new ridged striker to fix thunk noises? My dealer doesn't believe that it would fix the thunk :-P

ken

[Gilly]

HEY! You said "striker" again. The part you want to replace is NOT the striker, the striker is attached down by the loading area. You want the LATCH.
I don't believe there was a TSB or SI on this problem, the tech rep told us about it, and that all the old style latches were pulled from inventory and replaced with the updated part.
I don't care if the dealer doesn't believe me. You could also have something else going on, I won't "guarantee" this will fix it, but I have gotten rid of a clunking noise in the tailgate latch area literally dozens of times by replacing the latch with the updated design.
I can't tell if yours is old or new style, you need to look in the V area where the striker enters the latch (can't see it in your picture, and probably too tight and dark to photograph well). If it's all smooth in the "pit" of the grooved area, it's old style, and if it's ribbed or notched (like the edge of a quarter, only larger grooves), then it's new style. You can also try smearing a little bearing grease in the pit of the groove and see if it stops for awhile. Usually it will at least temporarily make the noise stop even with the old latch. The new latch is a permanant fix, I would still put a little grease in there on a new latch.
Gilly

[kenyee]

Originally Posted by Gilly

HEY! You said "striker" again

Agh! I'll get the terminology right eventually :-)

Originally Posted by Gilly

I don't care if the dealer doesn't believe me

Actually, the problem is, they don't believe me :-P
They've adjusted the rubber stops (w/ the interior panel off because they thought the panel was the problem) and the noise has gotten a lot more intermittent, so I think the latch is the likely culprit.

Originally Posted by Gilly

If it's all smooth in the "pit" of the grooved area, it's old style, and if it's ribbed or notched (like the edge of a quarter, only larger grooves), then it's new style.

I'll feel it and get a pic of the area for the thread so others know what to look for. I'll also stop by a dealer and check out a latch on the latest ones and see if I can get a pic that will come out.
I'll see if I can find some grease to try on it too.

thanks,

ken

[Gilly]

If you have conditions that are "just right" you can also diagnose this by driving with the hatch open and see if you notice the noise is gone. Can be tough though due to excess noise from the open hatch. Depends on how loud it is. If the noise is from something else (outside the truck, suspension, etc) then it may even seem louder, but usually most peoples hearing will kind of sense it's outside not inside. Greasing it is a good first step, and if that cures it I'd replace the latch. You can tell if it's old or new by looking, no need to put'cher finger in it!
Gilly

[kenyee]

Ha! I finally got a picture of the ridged part! It's a little fuzzy, but you can see the grooves. It's also easiest if you put your finger in it and feel it...it's really dark and hard to see, even in daylight, unless you use a flashlight.

Guess it's not the latch on the rear hatch door. I'll fiddle w/ the striker which looks uncentered.

[Gilly]

You could still try a little grease, looks like it was never greased at all. Just like wheel bearing grease, not a big glob, just a "smear" on each side.
Gilly